It is common practice in the graphic arts industry to gather or collect sheets from various stacks and to do so on a conveyor or along a raceway which moves adjacent the various stacks while each stack contributes a sheet onto the raceway. One example of that prior art is seen in U.S. Pat. No. 3,510,119 which simply shows a plurality of sheet stacks in a line and a conveyor moving past the stacks to collect a sheet from each stack and thereby form a final magazine or book or the like. In the prior art arrangement, the collected sheets are laid flat on the raceway or collecting conveyor, and thus the full-length or width (depending upon orientation of the sheet) of the sheet occupies the corresponding length of the collecting conveyor or raceway. This means that the speed of movement of the collecting conveyor or raceway must be slow enough to correspond with the feeding equipment which is depositing the sheet onto the collecting conveyor or raceway so that each deposited sheet can be properly positioned thereon. Also, the prior art system drops the sheets in a flat orientation and thus an airplane effect is created, and therefore the sheets must also be collected at speeds which allow for that impediment.
In the prior art systems, it is common practice to operate at maximum speeds which produce 300 books per minute, and this requires a collecting conveyor or raceway speed of 450 feet per minute, for common dimensions of the sheet being collected. With the present invention which avoids the flat or horizontal collecting position for the sheet, the collecting conveyor or raceway speed can be as slow as 75 feet per minute, and that is less than 17% of the aforementioned prior art speed while still collecting the same quantity of books, as mentioned.
Accordingly, it is an object of this invention to provide an improved method and apparatus for collecting sheets at a speed higher then that heretofore possible, and to also accomplish this objective while collecting the sheets in a more accurately aligned manner than that heretofore possible.
Still further, the present invention provides for the high speed collection mentioned and to do so with more compact equipment and thus less space being required.
Further, since the collecting conveyor or raceway of this invention needs to move only at a fraction of the speed of the prior art equipment, the method and apparatus of this invention provides for a greater quantity of books produced per unit of time than that possible with prior art equipment, such as far exceeding the prior art production rate of 300 books per minute.
Still further, the present invention provides a method and apparatus for collecting books of varying sizes but at the high speed and in the compact nature mentioned herein.